Merge pull request #296 from NitorCreations/add-application-listener-…

…to-netty

Add support for adding ApplicationListener when starting netty

CHANGELOG.md

@@ -23,6 +23,7 @@
 - Fix workflow history cleanup to keep the actions that hold the latest values of state variables
 - nFlow Explorer: Custom content to workflow definition and workflow instance pages. 
 - nFlow Explorer: Executors page to use standard time formatting in tooltips 
+- nFlow netty: Add support for registering Spring ApplicationListeners
 
 ## 5.3.3 (2019-02-04)
 

nflow-netty/src/main/java/io/nflow/netty/StartNflow.java

@@ -17,6 +17,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationListener;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.core.env.SimpleCommandLinePropertySource;
 import org.springframework.core.io.support.ResourcePropertySource;
@@ -35,6 +36,8 @@ public class StartNflow {
 
   private final Set<Class<?>> annotatedContextClasses = new LinkedHashSet<>();
 
+  private final List<ApplicationListener<?>> applicationListeners = new LinkedList<>();
+
   private final List<ResourcePropertySource> propertiesSources = new LinkedList<>();
 
   public static void main(String[] args) throws Exception {
@@ -52,20 +55,25 @@ public static void main(String[] args) throws Exception {
     new StartNflow().startNetty(argsMap);
   }
 
-  public StartNflow registerSpringContext(Class<?>... springContextClass) {
-    annotatedContextClasses.addAll(asList(springContextClass));
+  public StartNflow registerSpringContext(Class<?>... springContextClasses) {
+    annotatedContextClasses.addAll(asList(springContextClasses));
+    return this;
+  }
+
+  public StartNflow registerSpringApplicationListener(ApplicationListener<?>... applicationListeners) {
+    this.applicationListeners.addAll(asList(applicationListeners));
     return this;
   }
 
-  public StartNflow registerSpringClasspathPropertySource(String... springPropertiesPath) throws IOException {
-    for (String path : springPropertiesPath) {
+  public StartNflow registerSpringClasspathPropertySource(String... springPropertiesPaths) throws IOException {
+    for (String path : springPropertiesPaths) {
       propertiesSources.add(new ResourcePropertySource(path));
     }
     return this;
   }
 
-  public StartNflow registerSpringPropertySource(ResourcePropertySource... springPropertySource) {
-    propertiesSources.addAll(asList(springPropertySource));
+  public StartNflow registerSpringPropertySource(ResourcePropertySource... springPropertySources) {
+    propertiesSources.addAll(asList(springPropertySources));
     return this;
   }
 
@@ -91,6 +99,7 @@ public ApplicationContext startNetty(Map<String, Object> properties) throws Exce
     annotatedContextClasses.add(DelegatingWebFluxConfiguration.class);
     annotatedContextClasses.add(NflowNettyConfiguration.class);
     context.register(annotatedContextClasses.stream().toArray(Class<?>[]::new));
+    applicationListeners.forEach(applicationListener -> context.addApplicationListener(applicationListener));
     context.refresh();
 
     // Start netty

nflow-netty/src/test/java/io/nflow/netty/StartNflowTest.java

@@ -1,25 +1,39 @@
 package io.nflow.netty;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
 
 import java.util.HashMap;
 import java.util.Map;
 
 import org.junit.Test;
 import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationListener;
+import org.springframework.context.event.ApplicationContextEvent;
 
 public class StartNflowTest {
 
+  public class TestApplicationListener implements ApplicationListener<ApplicationContextEvent> {
+    public ApplicationContextEvent applicationContextEvent;
+    @Override
+    public void onApplicationEvent(ApplicationContextEvent applicationContextEvent) {
+      this.applicationContextEvent = applicationContextEvent;
+    }
+  }
+
   @Test
   public void startNflowNetty() throws Exception {
+    TestApplicationListener testListener = new TestApplicationListener();
     StartNflow startNflow = new StartNflow().registerSpringContext(this.getClass())
-        .registerSpringClasspathPropertySource("external.properties");
+        .registerSpringClasspathPropertySource("external.properties")
+        .registerSpringApplicationListener(testListener);
     Map<String, Object> properties = new HashMap<>();
     properties.put("nflow.db.create_on_startup", false);
     properties.put("nflow.autostart", false);
     properties.put("nflow.autoinit", false);
     ApplicationContext ctx = startNflow.startNetty(7500, "local", "", properties);
 
+    assertNotNull(testListener.applicationContextEvent);
     assertEquals("7500", ctx.getEnvironment().getProperty("port"));
     assertEquals("local", ctx.getEnvironment().getProperty("env"));
     assertEquals("externallyDefinedExecutorGroup", ctx.getEnvironment().getProperty("nflow.executor.group"));